There are construction machines, such as a hydraulic shovel with a crawler-type lower traveling body, which have a pair of left and right traveling devices, left and right manipulators for traveling that are operated to drive the left and right traveling devices respectively (left and right pedals for traveling and lever for traveling, in the case of a hydraulic shovel), a work device for executing a variety of work such as excavation, and a manipulator for work operated to drive the work device (a joystick operating lever provided on each of the left and right sides of the operator's seat, in the case of a hydraulic shovel).
The operator of such a construction machine needs to continuously operate the left and right manipulators for traveling while the chassis of the construction machine is traveling. For example, when a traveling operation is executed using the left and right pedals for traveling, these left and right pedals for traveling need to be constantly stepped on while the construction machine is traveling, and the longer the traveling distance, the longer the time the pedals need to be stepped on, leading to the accumulation of fatigue in the operator, partly because a construction site where the construction machine is used has rough ground.
There have conventionally been known a technique in which the operator's cab is provided with a selector switch for cruise control and the left and right traveling devices are advanced straight ahead at a constant speed by operating the selector switch (see PTL 1, for example), and a technique in which the grips of the left and right operating levers for work on the left and right sides of the operator's seat are provided with variable output switches and the left and right traveling devices are driven by operating these switches (see PTL 2, for example).